Flexible printed circuit board, backlight unit using the same, and liquid crystal display device comprising the same

Abstract

A flexible printed circuit board (FPCB) capable of improving strength is disclosed, the FPCB comprising a base film; a copper layer on the base film, the copper layer including a circuit pattern, and a strength-reinforcing pattern in an area without the circuit pattern; and a coverlay film on the copper layer.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims the benefit of the Korean Patent Application No. 10-2009-0121031 filed on Dec. 8, 2009, which is hereby incorporated by reference as if fully set forth herein.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to a printed circuit board (PCB), and more particularly, to a flexible printed circuit board (FPCB).[0004]2. Discussion of the Related Art[0005]A printed circuit board (hereinafter, referred to as ‘PCB’) is used to electrically connect or support electronic components on a blank substrate according a circuit design of electric wiring or traces. The PCB may be largely classified into a rigid PCB (RPCB), a flexible PCB (FPCB), and a special board.[0006]The FPCB allows an efficient arrangement in a limited space of the electronic device, and also enables small-sized and light-weight electronic device. Furthermore, the FPCB is advantages in that it can be designed in var...

AI Technical Summary

Benefits of technology

[0013]Another advantage of the present invention is to provide a backlight unit which facilitates to realize slimness of LCD device through the use of FPCB, and an LCD device using the backlight unit.

[0014]A further advantage of the present invention is to provide a backlight unit which facilitates to improve a thermal conductivity of FPCB, and an LCD device using the backlight unit.

[0015]Additional advantages and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

[0016]To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a flexible printed circuit board (FPCB) comprising a base film; a copper layer on the base film, the copper layer including a circuit pattern, and a strength-reinforcing pattern in an area without the circuit pattern; and a coverlay film on the copper layer.

[0017]In another aspect of the present invention, there is provided a backlight unit comprising a light-guiding plate with at least one side corresponding to a light-incidence face; a first FPCB confronting the light-incidence face; at least one LED for emitting light to the light-incidence face, the at least one LED positioned on one surface of the first FPCB; a second FPCB connected to an opposite surface to the one surface of the first FPCB; a connector for supplying externally-provided driving power to the at least one LED, the connector positioned on one surface of the second FPCB; and an optical sheet for improving luminance of light advancing from the light-guiding plate.

[0018]In another aspect of the present invention, there is provided a liquid crystal panel for displaying images by controlling light transmittance; and a backlight unit for emitting light to the liquid crystal panel, wherein the backlight unit comprises a light-guiding plate with at least one side corresponding to a light-incidence face; a first FPCB confronting the light-incidence face; at least one LED for emitting light to the light-incidence face, the at least one LED positioned on one surface of the first FPCB; a second FPCB connected to an opposite surface to the one surface of the first FPCB; a connector for supplying externally-provided driving power to the at least one LED, the connector positioned on one surface of the second FPCB; and an optical sheet for improving luminance of light advancing from the light-guiding plate.

Problems solved by technology

However, when the heavy electronic components are placed on the FPCB, or the large force is applied to the FPCB, the FPCB is apt to be severed due to its low structural strength.

However, the thick film adhered to enhance the strength of the related art FPCB may cause the deterioration of thermal properties.

Furthermore, a manufacturing cost is increased due to an additional process for adherence of the thick film.

Thus, heat generated from the LEDs is not smoothly transmitted, whereby efficiency of LEDs may be deteriorated, or the LCD device may be warped or distorted.

Images